using System;
using System.Configuration;
using System.Data;
using System.Data.OracleClient;
using System.Collections;
using System.Collections.Generic;

namespace OracleHelper
{
    public class OraHelper
    {
        public OraHelper()
        {
        }
        public OraHelper(string connectionString)
        {
            m_connection = new OracleConnection(connectionString);
        }

        private OracleConnection m_connection = null;
        public OracleConnection OraConnection
        {
            get { return m_connection; }
            set { m_connection = value; }
        }

        #region Open & Close

        public void Open()
        {
            if (m_connection.State != ConnectionState.Open)
                m_connection.Open();
        }
        public void Close()
        {
            if (m_connection.State != ConnectionState.Closed)
                m_connection.Close();
        }

        #endregion

        #region Transaction

        public OracleTransaction BeginTransaction()
        {
            return m_connection.BeginTransaction();
        }

        #endregion

        #region ExecuteNonQuery
        /// <summary>
        /// Execute a database query which does not include a select
        /// </summary>
        /// <param name="cmdType">Command type either stored procedure or SQL</param>
        /// <param name="cmdText">Acutall SQL Command</param>
        /// <param name="commandParameters">Parameters to bind to the command</param>
        /// <returns></returns>
        public int ExecuteNonQuery(CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
        {
            // Create a new Oracle command
            OracleCommand cmd = new OracleCommand();


            //Prepare the command
            PrepareCommand(cmd, null, cmdType, cmdText, commandParameters);

            //Execute the command
            int val = cmd.ExecuteNonQuery();

            //Close the connection
            m_connection.Close();
            //Clear Parameters
            cmd.Parameters.Clear();

            return val;
        }
        public int ExecuteNonQuery(string cmdText, params OracleParameter[] commandParameters)
        {
            return this.ExecuteNonQuery(CommandType.Text, cmdText, commandParameters);
        }

        /// <summary>
        /// Execute an OracleCommand (that returns no resultset) against an existing database transaction 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
        /// </remarks>
        /// <param name="trans">an existing database transaction</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or PL/SQL command</param>
        /// <param name="commandParameters">an array of OracleParamters used to execute the command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public int ExecuteNonQuery(OracleTransaction trans, CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
        {
            OracleCommand cmd = new OracleCommand();
            PrepareCommand(cmd, trans, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }
        public int ExecuteNonQuery(OracleTransaction trans, string cmdText, params OracleParameter[] commandParameters)
        {
            return this.ExecuteNonQuery(trans, CommandType.Text, cmdText, commandParameters);
        }


        #region Dictionary Parameter
        public int ExecuteNonQuery(CommandType cmdType, string cmdText, IDictionary paramsDict)
        {
            List<OracleParameter> listParams = new List<OracleParameter>();
            foreach (DictionaryEntry item in paramsDict)
            {
                listParams.Add(new OracleParameter(item.Key.ToString(), item.Value));
            }
            return this.ExecuteNonQuery(cmdType, cmdText, listParams.ToArray());
        }
        public int ExecuteNonQuery(string cmdText, IDictionary paramsDict)
        {
            return this.ExecuteNonQuery(CommandType.Text, cmdText, paramsDict);
        }
        //Support Transaction
        public int ExecuteNonQuery(OracleTransaction trans, CommandType cmdType, string cmdText, IDictionary paramsDict)
        {
            List<OracleParameter> listParams = new List<OracleParameter>();
            foreach (DictionaryEntry item in paramsDict)
            {
                listParams.Add(new OracleParameter(item.Key.ToString(), item.Value));
            }
            return this.ExecuteNonQuery(trans, cmdType, cmdText, listParams.ToArray());
        }
        public int ExecuteNonQuery(OracleTransaction trans, string cmdText, IDictionary paramsDict)
        {
            return this.ExecuteNonQuery(trans, CommandType.Text, cmdText, paramsDict);
        }
        #endregion


        #endregion

        #region ExecuteReader
        /// <summary>
        /// Execute a select query that will return a result set
        /// </summary>
        /// <param name="connString">Connection string</param>
        //// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or PL/SQL command</param>
        /// <param name="commandParameters">an array of OracleParamters used to execute the command</param>
        /// <returns></returns>
        public OracleDataReader ExecuteReader(CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
        {

            //Create the command and connection
            OracleCommand cmd = new OracleCommand();

            try
            {
                //Prepare the command to execute
                PrepareCommand(cmd, null, cmdType, cmdText, commandParameters);

                //Execute the query, stating that the connection should close when the resulting datareader has been read
                OracleDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;

            }
            catch
            {

                //If an error occurs close the connection as the reader will not be used and we expect it to close the connection
                m_connection.Close();
                throw;
            }
        }
        public OracleDataReader ExecuteReader(string cmdText, params OracleParameter[] commandParameters)
        {

            //Create the command and connection
            OracleCommand cmd = new OracleCommand();

            try
            {
                //Prepare the command to execute
                PrepareCommand(cmd, null, CommandType.Text, cmdText, commandParameters);

                //Execute the query, stating that the connection should close when the resulting datareader has been read
                OracleDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;

            }
            catch
            {

                //If an error occurs close the connection as the reader will not be used and we expect it to close the connection
                m_connection.Close();
                throw;
            }
        }

        #region Dictionary Parameter
        public OracleDataReader ExecuteReader(CommandType cmdType, string cmdText, IDictionary paramsDict)
        {
            List<OracleParameter> listParams = new List<OracleParameter>();
            foreach (DictionaryEntry item in paramsDict)
            {
                listParams.Add(new OracleParameter(item.Key.ToString(), item.Value));
            }
            return this.ExecuteReader(cmdType, cmdText, listParams.ToArray());

        }
        public OracleDataReader ExecuteReader(string cmdText, IDictionary paramsDict)
        {
            return this.ExecuteReader(CommandType.Text, cmdText, paramsDict);
        }
        #endregion

        #endregion

        #region ExecuteScalar

        /// <summary>
        /// Execute an OracleCommand that returns the first column of the first record against the database specified in the connection string 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new OracleParameter(":prodid", 24));
        /// </remarks>
        /// <param name="connectionString">a valid connection string for a SqlConnection</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or PL/SQL command</param>
        /// <param name="commandParameters">an array of OracleParamters used to execute the command</param>
        /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
        public object ExecuteScalar(CommandType cmdType, string cmdText, params OracleParameter[] commandParameters)
        {
            OracleCommand cmd = new OracleCommand();

            PrepareCommand(cmd, null, cmdType, cmdText, commandParameters);
            object val = cmd.ExecuteScalar();
            m_connection.Close();
            cmd.Parameters.Clear();
            return val;
        }
        public object ExecuteScalar(string cmdText, params OracleParameter[] commandParameters)
        {
            return this.ExecuteScalar(CommandType.Text, cmdText, commandParameters);
        }

        ///	<summary>
        ///	Execute	a OracleCommand (that returns a 1x1 resultset)	against	the	specified SqlTransaction
        ///	using the provided parameters.
        ///	</summary>
        ///	<param name="transaction">A	valid SqlTransaction</param>
        ///	<param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        ///	<param name="commandText">The stored procedure name	or PL/SQL command</param>
        ///	<param name="commandParameters">An array of	OracleParamters used to execute the command</param>
        ///	<returns>An	object containing the value	in the 1x1 resultset generated by the command</returns>
        public object ExecuteScalar(OracleTransaction transaction, CommandType commandType, string commandText, params OracleParameter[] commandParameters)
        {
            if (transaction == null)
                throw new ArgumentNullException("transaction");
            if (transaction != null && transaction.Connection == null)
                throw new ArgumentException("The transaction was rollbacked	or commited, please	provide	an open	transaction.", "transaction");

            // Create a	command	and	prepare	it for execution
            OracleCommand cmd = new OracleCommand();

            PrepareCommand(cmd, transaction, commandType, commandText, commandParameters);

            // Execute the command & return	the	results
            object retval = cmd.ExecuteScalar();

            // Detach the SqlParameters	from the command object, so	they can be	used again
            cmd.Parameters.Clear();
            return retval;
        }
        public object ExecuteScalar(OracleTransaction transaction, string commandText, params OracleParameter[] commandParameters)
        {
            return this.ExecuteScalar(transaction, CommandType.Text, commandText, commandParameters);
        }

        #region Dictionary Parameter
        public object ExecuteScalar(CommandType cmdType, string cmdText, IDictionary paramsDict)
        {
            List<OracleParameter> listParams = new List<OracleParameter>();
            foreach (DictionaryEntry item in paramsDict)
            {
                listParams.Add(new OracleParameter(item.Key.ToString(), item.Value));
            }
            return this.ExecuteScalar(cmdType, cmdText, listParams.ToArray());
        }
        public object ExecuteScalar(string cmdText, IDictionary paramsDict)
        {
            return this.ExecuteScalar(CommandType.Text, cmdText, paramsDict);
        }
        //Support Transcation
        public object ExecuteScalar(OracleTransaction transaction, CommandType commandType, string commandText, IDictionary paramsDict)
        {
            List<OracleParameter> listParams = new List<OracleParameter>();
            foreach (DictionaryEntry item in paramsDict)
            {
                listParams.Add(new OracleParameter(item.Key.ToString(), item.Value));
            }
            return this.ExecuteScalar(transaction, commandType, commandText, listParams.ToArray());
        }
        public object ExecuteScalar(OracleTransaction transaction, string commandText, IDictionary paramsDict)
        {
            return this.ExecuteScalar(transaction, CommandType.Text, commandText, paramsDict);
        }
        #endregion


        #endregion

        #region ExecuteDataset


        /// <summary>
        /// Execute a OracleCommand (that returns a resultset)
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new OracleParameter(":prodid", 24));
        /// </remarks>
        public DataSet ExecuteDataset(CommandType commandType, string commandText, params OracleParameter[] commandParameters)
        {
            // Create a command and prepare it for execution
            OracleCommand cmd = new OracleCommand();
            PrepareCommand(cmd, null, commandType, commandText, commandParameters);

            // Create the DataAdapter & DataSet
            using (OracleDataAdapter da = new OracleDataAdapter(cmd))
            {
                DataSet ds = new DataSet();

                // Fill the DataSet using default values for DataTable names, etc
                da.Fill(ds);

                //Close the connection
                this.Close();

                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                // Return the dataset
                return ds;
            }
        }
        public DataSet ExecuteDataset(string commandText, params OracleParameter[] commandParameters)
        {
            return this.ExecuteDataset(CommandType.Text, commandText, commandParameters);
        }

        #region Dictionary Paramter
        public DataSet ExecuteDataset(CommandType commandType, string commandText, IDictionary paramsDict)
        {
            List<OracleParameter> listParams = new List<OracleParameter>();
            foreach (DictionaryEntry item in paramsDict)
            {
                listParams.Add(new OracleParameter(item.Key.ToString(), item.Value));
            }
            return this.ExecuteDataset(commandType, commandText, listParams.ToArray());
        }
        public DataSet ExecuteDataset(string commandText, IDictionary paramsDict)
        {
            return this.ExecuteDataset(CommandType.Text, commandText, paramsDict);
        }
        #endregion


        #endregion

        #region CacheParameters

        //Create a hashtable for the parameter cached
        private Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

        /// <summary>
        /// Add a set of parameters to the cached
        /// </summary>
        /// <param name="cacheKey">Key value to look up the parameters</param>
        /// <param name="commandParameters">Actual parameters to cached</param>
        public void CacheParameters(string cacheKey, params OracleParameter[] commandParameters)
        {
            parmCache[cacheKey] = commandParameters;
        }

        /// <summary>
        /// Fetch parameters from the cache
        /// </summary>
        /// <param name="cacheKey">Key to look up the parameters</param>
        /// <returns></returns>
        public OracleParameter[] GetCachedParameters(string cacheKey)
        {
            OracleParameter[] cachedParms = (OracleParameter[])parmCache[cacheKey];

            if (cachedParms == null)
                return null;

            // If the parameters are in the cache
            OracleParameter[] clonedParms = new OracleParameter[cachedParms.Length];

            // return a copy of the parameters
            for (int i = 0, j = cachedParms.Length; i < j; i++)
                clonedParms[i] = (OracleParameter)((ICloneable)cachedParms[i]).Clone();

            return clonedParms;
        }

        #endregion

        /// <summary>
        /// Internal function to prepare a command for execution by the database
        /// </summary>
        /// <param name="cmd">Existing command object</param>
        /// <param name="conn">Database connection object</param>
        /// <param name="trans">Optional transaction object</param>
        /// <param name="cmdType">Command type, e.g. stored procedure</param>
        /// <param name="cmdText">Command test</param>
        /// <param name="commandParameters">Parameters for the command</param>
        private void PrepareCommand(OracleCommand cmd, OracleTransaction trans, CommandType cmdType, string cmdText, OracleParameter[] commandParameters)
        {

            //Open the connection if required
            if (m_connection.State != ConnectionState.Open)
                m_connection.Open();

            //Set up the command
            cmd.Connection = m_connection;
            cmd.CommandText = cmdText;
            cmd.CommandType = cmdType;

            //Bind it to the transaction if it exists
            if (trans != null)
                cmd.Transaction = trans;

            // Bind the parameters passed in
            if (commandParameters != null)
            {
                foreach (OracleParameter parm in commandParameters)
                    cmd.Parameters.Add(parm);
            }
        }

        /// <summary>
        /// Converter to use boolean data type with Oracle
        /// </summary>
        /// <param name="value">Value to convert</param>
        /// <returns></returns>
        public static string OraBit(bool value)
        {
            if (value)
                return "Y";
            else
                return "N";
        }

        /// <summary>
        /// Converter to use boolean data type with Oracle
        /// </summary>
        /// <param name="value">Value to convert</param>
        /// <returns></returns>
        public static bool OraBool(string value)
        {
            if (value.Equals("Y"))
                return true;
            else
                return false;
        }


    }

}
